This is a nice PR piece: timed for a specific holiday on the calender (timely), hooks into larger discussion around manners and the "best way" to greet somebody (social hook), and ends up with real-world data on conversion ratios. (Give us the numbers!). Very nicely done.

Interesting trivia point: originally the phrase was "Happy Christmas," see "The Night Before Christmas" for a source. Can't help but wonder how "Happy Christmas" compares to the others?